Pneumatic action for musical instruments



C. V. JAMESON.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

APPLICATION flLED MAY 24, 1918.

1,367,263. Patented Feb. 1,1921.

UNITED STATES PATENT OFFICE.

CHARLES V. JAMESON, OF CHICAGO, ILLINOIS.

PNEUMATIC ACTION FOR Application filed May 24,

l/ '0 all 207mm it may concern:

Be it known that I, Ci-niRLns V. JAMnsoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of .lllinois, have invented new and useful Improvements in Pneumatic Actions for Musical Instruments, of which the following is a specification.

This invention relates to the pneumatic actions of player pianos and other automatic musical instruments,

One of its objects is to simplify the construction and reduce the cost of manufacture of such actions.

Another object is the production of a practically jointless valve-block or board, in order to reduce liability of air-leakage to the minimum.

A further object is to render the pouches or diaph agm-pneumatics easy of access to facilitate their repair and r newal.

In the accompanying drawings: Figure 1 is a transverse section of the improved action and associated parts. Fig. 2 is a fragmentary front View, partly in section, of the channel-board. Fig. 3 is a rear view, partly in section, of one of the valve-blocks, on an enlarged scale. Fig. 4 is a sectional bottom plan view thereof.

Similar characters of reference indicate corresponding parts throughout the several views.

1 indicates the keys of a player piano, 2 the shank of one of the hammers of the piano action, 3 the wippen, 3 the jack and f the abstract.

The frame or body of the wind chest shown in the drawings comprises upright end pieces or standards 5, a longitudinal base strip or board 6 connecting the lower portions of said standards and longitudinal upper strips 7, 8 and 9, connecting their upper portions. This frame may however be of any other suitable construction.

In its general organization, the pneumatic action comprises a fixed upright longitudinal channel board 10, rows of striker pneumatics 11 mounted on the rear side of said board, and corresponding rows of valve blocks or units 12 mounted on the front side of said board. These pneumatics are carried by horizontal channel boards or shelves 13 to the undersides of which their fixed boards are glued or otherwise fastened, in the particular construction shown in the drawings. The upright channel board 10 is suitably Specification of Letters Patent.

MUSICAL INSTRUMENTS.

Patented Feb. 1, 1921.

1918. Serial No. 236,426.

fastened to the standards 5 and the strips 6 and 9 and is provided with longitudinal vacuum. channels or chambers 1%, one for each row of valve-blocks and the companion striker pneumatics. The several vacuum channels communicate at their ends with upright manifold passages 15 which are connected with the usual main exhaust bellows, not shown, by one or more trunks 16, so that Sold channels 14: are constantly exhausted during the operation of the instrument.

The valve-blocks or units are detachably secured to the channel board 10 by screws 17 or other fastening means. These units may be of any suitable construction, but that shown in the drawings is preferred. Each block contains a lower pouch chamber 18 connected by a passage 19 with the corresponding vacuum channel 1a of the board 10, and an upper valve chamber 20 connected with the corresponding striker pneumatic 11 by a channel 2O extending transversely through said channel board and the corresponding shelf 13 above the companion passage 19. The passage 19 and channel 20 of each block are arranged one above the other and both extend through the rear side of the block. A flushing port 21 connects the chamber 20 with the atmosphere. The partition 22 of the block contains the vacuum port 28. Located in the upper valvechamber is the usual duplex valve 24, the heads of which cooperate with the vacuum and vent ports 23 and 21 respectively, to open the one when the other is closed and thereby collapse or inflate the correspond ing striker pneumatic 11, in a common manner. I

25 indicates the customary valve-operating pouch or pneumatic arranged in the lower chamber of the block. This pouchchamber extends to the bottom or lower surface of the block and is provided at its lower end with a marginal recess or rabbet 28 forming an internal shoulder 29 against which the margin of the pouch bears. Seated in this recess against the outer or underside of the pouch-margin is a retaining ring 80 which may be driven into the recess or otherwise secured therein. Preferably, the pouch is first glued to the ring to facilitate manipulation of these parts. Glue is then applied to the walls of the recess and the ring is finally driven into the latter. The outer face of the ring is flush with the face of the block and a sealing sheet 31 of paper or other suitable material is glued to said face over the ring and the pouch, to form an air-tight chamber 32 underneath the pouch. Leading from the corresponding tracker duct 33 to this chamber is the usual tube 33*. In the preferred construction shown, this tube is connected at its lower end to a passage 34 formed in the block, and this passage communicates with the chamber beneath the pouch by a notch or transverse passage 35 in the underside of the ring.

By locating the pouch in a recess which extends to or opens at the bottom or other surface of the block, the pouch is convenientl accessible for repairing or renewing it. his can be readily done without dismembering parts of the block, as required in previous constructions, it being only necessary to tear off the covering sheet 31 and remove the ring 30, and to substitute a fresh sheet after replacing or renewing the pouch.

The partition 22 of the block is formed integral therewith by boring the block from opposite sides, producing a single-piece structure which avoids the use of joints and prevents leakage. This also materially simplifies the construction of the valve-block and reduces its cost.

If desired, the retaining ring 30 may in some cases be omitted and the margin of the pouch simply glued to the shoulder 29.

\Vhile the invention is herein shown and described in connection with an action having separate valve-units or blocks, it is equally applicable to so-called layer actions in which each of the superposed layers or boards contains a row of valve chambers. The expression block or the like, used in the appended claims, is intended to include both forms of actions.

I do not wish to claim in this application the construction of the stickers and their stop devices herein shown, as the same forms the subject of another application for pat ent filed by me October 10, 1917, Serial N 0. 195,666.

I claim as my invention:

1. A valve and pouch unit for pneumatic musical instruments, comprisin an integral, jointless block provided with a valve chamber, a pouch chamber containing ,a pouch, an atmospheric chamber underneath the pouch and a passage leading to said atmospheric chamber, a frangible sealing sheet applied to the block over said atmospheric chamber, said valve chamber having suction and flushing ports, and valves controlling said ports, said sealing sheet being uncovered and exposed for ready access thereto and the pouch being accessible upon tearing off said sheet.

2. A valve and pouch unit for pneumatic musical instruments, comprising an integral, jointlcss block provided with a valve chamber, a pouch chamber containing a pouch, an atmospheric chamber underneath the pouch and a passage leading to said atmospherio chamber, a frangible sealing sheet applied to the block over said atmospheric chamber, said valve chamber having suction and flushing ports, and valves controlling said ports, said block having an exhaust passage extending through its rear side and communicating with said pouch chamber and a channel extending through the rear side of the block above said exhaust passage and communicating with said valve chamher.

3. A valve block or the like, containing a valve chamber and a pouch chamber, said valve-chamber having suction and fiushin ports, valves controlling said ports, sai pouch chamber extending to the surface of the block and having a recess forming an internal shoulder, a pouch controlling said valves and arranged in said recess and a retaining ring seated in said recess against the margin of the pouch, said block having an air passage for communication with a tracker-duct, and said ring being provided with a transverse passage communicating with said air passage.

CHARLES V. JAMESON. 

